From ef67c5758a3eeeac2a4cf57559ff967210f7feab Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sun, 27 Jan 2008 22:40:39 +0000 Subject: [PATCH] microcom: update from the author --- miscutils/microcom.c | 208 ++++++++++++++++++++++++++++--------------- 1 file changed, 134 insertions(+), 74 deletions(-) diff --git a/miscutils/microcom.c b/miscutils/microcom.c index 1235f0634..160bff19b 100644 --- a/miscutils/microcom.c +++ b/miscutils/microcom.c @@ -9,128 +9,188 @@ */ #include "libbb.h" +/* All known arches use small ints for signals */ +static volatile smallint signalled; + +static void signal_handler(int signo) +{ + signalled = signo; +} + +// set canonical tty mode +static void xget1(int fd, struct termios *t, struct termios *oldt) +{ + tcgetattr(fd, oldt); + *t = *oldt; + cfmakeraw(t); +// t->c_lflag &= ~(ISIG|ICANON|ECHO|IEXTEN); +// t->c_iflag &= ~(BRKINT|IXON|ICRNL); +// t->c_oflag &= ~(ONLCR); +// t->c_cc[VMIN] = 1; +// t->c_cc[VTIME] = 0; +} + +static int xset1(int fd, struct termios *tio, const char *device) +{ + int ret = tcsetattr(fd, TCSANOW, tio); + + if (ret) { + bb_perror_msg("can't tcsetattr for %s", device); + } + return ret; +} + int microcom_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int microcom_main(int argc, char **argv) { struct pollfd pfd[2]; -#define sfd (pfd[1].fd) - char *device_lock_file = NULL; - const char *s; + int nfd; + //int sfd; +#define sfd (pfd[0].fd) + char *device_lock_file; const char *opt_s = "9600"; - unsigned speed; - int len; - int exitcode = 1; + speed_t speed; + const char *opt_t = "100"; // 0.1 sec timeout + unsigned timeout; struct termios tio0, tiosfd, tio; + bool istty; - getopt32(argv, "s:", &opt_s); + // fetch options + opt_complementary = "-1"; /* at least one arg should be there */ + getopt32(argv, "s:t:", &opt_s, &opt_t); argc -= optind; argv += optind; - if (!argv[0]) - bb_show_usage(); + + // check sanity speed = xatou(opt_s); + timeout = xatou(opt_t); + device_lock_file = (char *)bb_basename(argv[0]); // try to create lock file in /var/lock - s = bb_basename(argv[0]); - if (!s[0]) { - errno = ENODEV; - bb_perror_msg_and_die("can't lock device"); - } - device_lock_file = xasprintf("/var/lock/LCK..%s", s); + device_lock_file = xasprintf("/var/lock/LCK..%s", device_lock_file); sfd = open(device_lock_file, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0644); if (sfd < 0) { - if (ENABLE_FEATURE_CLEAN_UP) - free(device_lock_file); - device_lock_file = NULL; if (errno == EEXIST) bb_perror_msg_and_die("can't lock device"); // We don't abort on other errors: /var/lock can be // non-writable or non-existent + if (ENABLE_FEATURE_CLEAN_UP) + free(device_lock_file); + device_lock_file = NULL; } else { // %4d to make mgetty happy. It treats 4-bytes lock files as binary, // not text, PID. Making 5+ char file. Brrr... - s = xasprintf("%4d\n", getpid()); + char *s = xasprintf("%4d\n", getpid()); write(sfd, s, strlen(s)); if (ENABLE_FEATURE_CLEAN_UP) - free((char*)s); + free(s); close(sfd); } + // setup signals + sig_catch(SIGHUP, signal_handler); + sig_catch(SIGINT, signal_handler); + sig_catch(SIGTERM, signal_handler); + sig_catch(SIGPIPE, signal_handler); + + // error exit code if we fail to open the device + signalled = 1; + // open device - sfd = open(argv[0], O_RDWR); - if (sfd < 0) { - bb_perror_msg("can't open device"); + sfd = open_or_warn(argv[0], O_RDWR | O_NOCTTY | O_NONBLOCK); + if (sfd < 0) goto unlock_and_exit; + fcntl(sfd, F_SETFL, O_RDWR | O_NOCTTY); + + /* put stdin to "raw mode" (if stdin is a TTY), + handle one character at a time */ + istty = isatty(STDIN_FILENO); + if (istty) { + xget1(STDIN_FILENO, &tio, &tio0); + if (xset1(STDIN_FILENO, &tio, "stdin")) + goto close_unlock_and_exit; +// tcflush(STDIN_FILENO, TCIFLUSH); + timeout = -1; // tty input? -> set infinite timeout for poll() } - // put stdin to "raw mode", handle one character at a time - tcgetattr(STDIN_FILENO, &tio0); - tio = tio0; - tio.c_lflag &= ~(ICANON|ECHO); - tio.c_iflag &= ~(IXON|ICRNL); - tio.c_oflag &= ~(ONLCR); - tio.c_cc[VMIN] = 1; - tio.c_cc[VTIME] = 0; - if (tcsetattr(STDIN_FILENO, TCSANOW, &tio)) { - bb_perror_msg("can't tcsetattr for %s", "stdin"); - goto unlock_and_exit; - } - - /* same thing for modem (plus: set baud rate) - TODO: make CLI option */ - tcgetattr(sfd, &tiosfd); - tio = tiosfd; - tio.c_lflag &= ~(ICANON|ECHO); - tio.c_iflag &= ~(IXON|ICRNL); - tio.c_oflag &= ~(ONLCR); - tio.c_cc[VMIN] = 1; - tio.c_cc[VTIME] = 0; - cfsetispeed(&tio, tty_value_to_baud(speed)); - cfsetospeed(&tio, tty_value_to_baud(speed)); - if (tcsetattr(sfd, TCSANOW, &tio)) { - bb_perror_msg("can't tcsetattr for %s", "device"); - goto unlock_and_exit; - } - - // disable SIGINT - signal(SIGINT, SIG_IGN); - - // drain stdin - tcflush(STDIN_FILENO, TCIFLUSH); - printf("connected to '%s' (%d bps), exit with ctrl-X...\r\n", argv[0], speed); + // same thing for modem + xget1(sfd, &tio, &tiosfd); + // order device to hang up at exit + tio.c_cflag |= (CREAD|HUPCL); + // set device speed + cfsetspeed(&tio, tty_value_to_baud(speed)); + if (xset1(sfd, &tio, argv[0])) + goto restore0_close_unlock_and_exit; // main loop: check with poll(), then read/write bytes across - pfd[0].fd = STDIN_FILENO; + /* pfd[0].fd = sfd; - they are the same */ pfd[0].events = POLLIN; - /*pfd[1].fd = sfd;*/ + pfd[1].fd = STDIN_FILENO; pfd[1].events = POLLIN; - while (1) { + + // TODO: on piped input should we treat NL as CRNL?! + + signalled = 0; + // initially we have to poll() both stdin and device + nfd = 2; + while (!signalled && nfd && safe_poll(pfd, nfd, timeout) > 0) { int i; - safe_poll(pfd, 2, -1); - for (i = 0; i < 2; ++i) { - if (pfd[i].revents & POLLIN) { - len = read(pfd[i].fd, bb_common_bufsiz1, COMMON_BUFSIZE); - if (len > 0) { - if (!i && 24 == bb_common_bufsiz1[0]) - goto done; // ^X exits - write(pfd[1-i].fd, bb_common_bufsiz1, len); + + for (i = 0; i < nfd; ++i) { + if (pfd[i].revents & (POLLIN | POLLHUP)) { +// int fd; + char c; + // read a byte + if (safe_read(pfd[i].fd, &c, 1) < 1) { + // this can occur at the end of piped input + // from now we only poll() for device + nfd--; + continue; } +// fd = STDOUT_FILENO; + // stdin requires additional processing + // (TODO: must be controlled by command line switch) + if (i) { + // ^@ sends Break + if (0 == c) { + tcsendbreak(sfd, 0); + continue; + } + // ^X exits + if (24 == c) + goto done; +// fd = sfd; + } + // write the byte + write(i ? sfd : STDOUT_FILENO, &c, 1); +// write(fd, &c, 1); + // give device a chance to get data + // wait 0.01 msec + // (TODO: seems to be arbitrary to me) + if (i) + usleep(10); } } } - done: +done: tcsetattr(sfd, TCSANOW, &tiosfd); - tcsetattr(STDIN_FILENO, TCSANOW, &tio0); - tcflush(STDIN_FILENO, TCIFLUSH); +restore0_close_unlock_and_exit: + if (istty) { +// tcflush(STDIN_FILENO, TCIFLUSH); + tcsetattr(STDIN_FILENO, TCSANOW, &tio0); + } + +close_unlock_and_exit: if (ENABLE_FEATURE_CLEAN_UP) close(sfd); - exitcode = 0; - unlock_and_exit: +unlock_and_exit: // delete lock file if (device_lock_file) { unlink(device_lock_file); if (ENABLE_FEATURE_CLEAN_UP) free(device_lock_file); } - return exitcode; + return signalled; }